NO762496L - - Google Patents

Description

Medical instrument for localization

and removal of obstructing objects

The present invention relates to a medical instrument for locating and removing obstructing objects, and more specifically be*-. voted an instrument that is particularly useful for locating and removing stones in the ureters and other obstructing objects in the body passages. The instrument in question includes a flexible tube or a sleeve in which a hard-twisted cable formed by several strands with a length longer than the tube is slidably placed.

right, whereby said cable is provided with an integrated cage part at the far end. The cage-shaped part, which is normally folded and hidden in the tube at its far end, can be pulled out beyond the tube to thereby assume an extended spiral-like, pear-shaped configuration with the help of which one can catch and extract stones in the urethra and other obstructions. objects. kabe-

len's tightly wound threads are arranged in a circumferential pattern around an axial cavity, which in one embodiment may be useful for liquid withdrawal or injection, and which in - — other embodiments may accommodate conductors for the transmission of light,

images and/or ultrasound energy. The sleeve or outer tube of the instrument is transparent and thereby makes it possible to visually check the spirally wound cable which is slidably placed therein. Appropriate markings on the cable, which are visible through the sheath's transparent wall, indicate the extent to which the instrument has been inserted during an intervention. The device is also provided with a handle for ejecting and retracting the cage and with suitable means for producing and emitting light and ultrasonic waves.

Methods and instruments for cystoscopic removal of . stones in the ureters are well documented in the medical literature, and perhaps to a lesser extent in the patent literature. Although the method of delivery has varied, in most cases it has involved distending, anesthetizing and lubricating the ureter, after which an attempt has been made to grab the stone and either crush it

or drag it out. Such an instrument which is previously known and which is described in US patent document 1,612,697 has the form of a flexible tube through which at least a pair of wires extend, whereby these wires are shaped in such a way at their far ends that they form a basket or a cage to catch stones in the ureters. Said instrument has later been modified so that a cage consisting of four has been obtained. threads, which threads spread and thereby form the cage when they emerge from the pipe, thanks to the natural springing ability of said threads. (N.E.J, of M. , vol 198, no. 12, 638-639 (1928). A similar instrument is described in Jour. A.M.A., 1907. - 1909

(1926); J. Urol., vol 37, 84 - 89 (1937); J. Urol., vol 60, 242 -

243 (1948); and in U.S. Patent No. 1,677,671. Later variants have included helical extractors to enable efficient gripping and extraction of the stones. Oak specimens are described in Jour. A.M.A. vol 114, pages 6-12 (1940);

J. Urol., vol 40, 83 - 100 (1938) and in US Patent No. 2,943,626.

Although ultrasound is quickly finding increased use in medicine, its use in the body areas belonging to the urinary and genital parts has been limited to investigations of kidney and bladder injuries. The researchers Lampert and Newman were the first to study ultrasonic crushing, and they successfully carried out laboratory experiments where they succeeded in breaking pieces of ice or crushing stones in the ureters of dogs and corpses (Yale J. Biol. Med., vol 27, 395

(1955); J. Uroi., vol 70, 704 (1953)). In 1973 published

Goodfriend reports on the first successful ultrasonic crushing and associated removal of a compressed stone in a ureter in a patient (Urology, vol.1, no. 3, 260 (1973).

The present invention thus relates to an improved instrument that is highly effective when it comes to locating, catching and removing obstructing objects from the ureters" or from other channels and vessels, whereby said instrument overcomes some of the shortcomings and disadvantages that have occurred by previously known instruments which have been calculated for the same purpose.

The instrument according to the invention comprises a smooth, flexible sleeve or tube through which a cable with tightly twisted wires extends. The length of the cable is greater than the length of the sleeve, and at the far end of the cable the wires are designed in such a way that they form a collapsible cage or basket. The wires of the cage are helically bent, and the cage as a whole has a clear pear-shaped contour that is large at the near end, so that the stones can easily enter this, and which is small at the far end so that stones that have once been introduced, cannot enter out. It has been shown that less force is required to spread adjacent threads at the enlarged end of the cage and that greater force is necessary to spread the threads at the smaller far end of the cage, which implies a clear advantage when it comes to capturing stones and preventing these in coming out when they are introduced in the middle of the cage.

The sleeve is transparent or translucent, and its diameter is considerably larger than the diameter of the twisted cable placed therein. Markings on the cable at selected points along its length are visible through the sleeve's transparent wall and give an accurate indication of the extent to which the instrument has been inserted, regardless of whether the cage is extended or retracted. Thanks to the annular space between the cable and the sleeve as well as the sleeve's transparency, slight tilting or bending movements of the cable in the sleeve when a stone or other object is caught, as well as changes in the twisting movement of the cable within the sleeve under such conditions, serve as visual indications of the instrument's work performance.

A particularly important aspect of the invention lies in the fact that the tightly wound wires in the cable are arranged in a circumferential pattern which forms a central cavity that runs along the cable's full extent from the wire cage to (and if necessary, beyond) the maneuvering handle. This cavity therefore forms a channel for draining fluid and for the introduction of dyes, medicines and other liquids. The cavity can also be used to receive conductive elements such as light-transmitting fibers and/or a transmitter line for ultrasound waves. This ultrasound waveguide is slidable in the cable's cavity, and it can thus be moved into direct contact with a stone or other object that is trapped in the cage. This direct contact enables the conductor to work efficiently, and that acoustic waves can be emitted directly to a stone to splinter it, whereby said contact helps to keep the stone back in the cage. The cage thus serves as a stop to hold the stone or other blocking object against movement in response to direct contact with the conductive element.

Other advantages and objectives of the invention will be apparent from the following detailed description in conjunction with the accompanying drawings on which

Fig. 1 shows in perspective an instrument which constitutes an embodiment of the invention, whereby said instrument is shown with the cage extended and in an extended position, Fig. 2 is a partial perspective drawing showing the far end of the instrument with the cage retracted and folded, Fig. 3 shows a along the line 3 - 3 in fig. 1 taken cross-section on an enlarged scale, Fig. 4 shows an enlarged, sectioned partial drawing in the longitudinal direction, whereby said figure shows the far part of the instrument with the cage extended, Fig. 5 is an enlarged, sectioned drawing in the longitudinal direction and shows it in fig. 4 visualized instrument feeding, Fig. 6 is an enlarged, sectional drawing in length the direction and shows the near end of the instrument according to fig. 5 with the addition of a light transmission element in the cable's cavity, whereby said light transmission element and its production and reception means are shown schematically, Fig. 7 is a along the line 7 - 7 in fig. 6 is a sectioned drawing on a larger scale, Fig. 8 is a partially schematic, sectioned partial drawing in the longitudinal direction and illustrates a further embodiment of the invention, and Fig. 9 is one along the line 9 - 9 in fig. 8 enlarged, sectioned drawing. -

In fig. 1-5, the term 10 generally denotes an instrument with a handle 11, an elongated flexible tube or sleeve 12, and a cable 13 extending through the sleeve. The length of the cable is considerably greater than the length of the sleeve 12, and the cable is designed near its far end in such a way that it forms an integrated and collapsible cage or basket 14.

The cable consists of several wires 15 which are wound or twisted to tight engagement in the circumferential direction, and in the longitudinal direction, as can best be seen from fig. 3-5. The single layer of wires defines a central cavity or channel 16 which extends along the length of the cable from the curve 14 to (and if necessary through) the handle 11. It is also seen that the outer dimensions of the cable, which are marked by a line enclosing the wires 15, are significantly smaller than the sleeve's 12 internal dimensions. Consequently, there is an annular space 17 between the outer surface of the cable and the inner surface of the sleeve.

Particularly effective results have been obtained with a cable with six wires, as shown, although it is entirely conceivable that a larger number of wires and possibly also a smaller number can be used. The wires can preferably be made of metal, and they should be flexible and corrosion-resistant, in addition to having good springing properties. A cobalt-nickel alloy marketed under the trade name "Elgiloy" by the American Gage & Machine Company, Elgin, Illinois, USA, has been found to be particularly suitable. However, other materials with similar properties can also be used.

The sleeve 12 consists of a transparent plastic material which is flexible, strong, physiologically compatible and resistant to heat, humidity and corrosion, besides having low coefficients of static friction and kinetic friction. Heat resistance is important where the possibility of treatment in an autoclave is required. Although some plastics may be suitable, fluorinated hydrocarbon (such as Teflon resin, marketed by E.I. du Pont de Nemours and Co., Wilmington, Delaware, USA) is considered particularly suitable. The term transparent is used here to denote materials that are sufficiently clear so that the cable can be seen visually through the wall of the sleeve, and the purpose is not to exclude material that is more generally considered transparent, but which in the relevant application area should be sufficiently clear to enable control.

The transparency of the sleeve is particularly important when it comes to visual control of the markings 18 - 21 which are arranged on the cable at selected distances from the cage 14. Each marking is distinctive. In the example shown, the first marking consists of a single dark part 18, the second marking 19 consists of a pair of such parts, the third marking 20 comprises three such parts, etc. The markings can be produced by applying a dye or other coating or impregnating agent on the cable, and if desired, different colors can be used to distinguish each marking in the markings arranged at a distance from each other. It will be seen that the markings in question are protected by the transparent sleeve and that they form a means of accurately determining the extent to which the cable is introduced into a body channel, regardless of whether any displacement occurs between the cable and the sleeve, i.e. regardless of whether the wire cage is extended or collapsed.

As can be seen from fig. 4, the cage 14 is largely pear-shaped in outline, whereby its widest dimension is located at the near end at the midpoint of the extended basket, counted in the longitudinal direction. The greater distance between adjacent threads at the cage's near end 14a facilitates the introduction of stones, while the smaller distance at the far end 14b helps to prevent the stones from escaping when they are captured. The greater bulging (sharper bending) at the near end also means that the force involved in separating adjacent threads is less, while greater force is required to spread the threads in question at the more tapered and less distant end. The spiral shape of each thread in the cage also helps to promote the introduction of a stone into the cage from its feeder (as a result of a twisting effect of the cage when it is pulled through the body passage) and to retain a stone in the cage (because there is no there is some straight longitudinal channel between the cage wires, through which a stone should be able to escape when the near and far ends of each cage wire are not in line with each other).

At the far end of the cage, the threads are surrounded and fixed by means of a connecting device which has the shape of a ring 22. The outer diameter of the ring is at most as large as the outer diameter of the plastic sleeve 12 (and preferably the same as this), and when the cage is folded together in the far end part of the sleeve, the outer side of the ring 22 will lie at the same level as the outer side of the sleeve, and in each case the outer side of the ring will protrude in the lateral direction, blocking the outer side of the sleeve. In the embodiment of the invention shown in the accompanying drawings, the cable 13 continues in tightly twisted helical form for a considerable distance beyond the ring 22, as indicated by reference

designation 23 in fig, 4, The elongated end part of the cable is inr-. closed in a plastic tube 24, and a rounded termination element 25 is attached to the outer end of the cable, the termination element 25, the tube 24, the cable's 23 and the connecting member 22 all in combination form a thread-shaped extension tip 26, and where the purpose of one such extension tip is to known way to facilitate re-insertion of the instrument if a stone is not captured on the first withdrawal. For those surgeons who prefer an instrument

which lacks a thread-shaped extension tip, the length of the cable's twisted end part 23 can be greatly reduced, besides the pipe 24 can be omitted, and the connecting element 25 can be placed immediately next to the ring 22, or alternatively the ring and connecting

connecting element is combined into a single terminating connecting element with the general design as element 25. Under all conditions, the diameter of the connecting element is the same as the diameter of the sleeve 12, and in those cases where a thread-shaped extension tip occurs, the tube 24 has the same cross-sectional dimension tions as the sleeve 12. The tube 24 can be made of the same flexible, transparent, tubular material as the sleeve 12, and if desired: the hardening of the twisted end portion 23 of the cable can be reduced by suitable treatment during the manufacturing process so that the wire-shaped extension tip can be bent by the surgeon to act - septable form to facilitate introduction and application.

The handle 11 essentially consists of a cylinder 27 which

is connected to the end of the sleeve 12 and a pressure piston 28 which is attached to the end of the cable 13. One sees in fig. 5 that the cylinder is said to consist of two parts 27a and 27b, which are screwed together and thereby lock the sleeve's outwardly directed feeding 12a. The pressure piston 28 has a spindle part 28a which is slidably movable in a bore 29

in the cylinder part 27b. The pressure piston is provided with an enlarged maneuvering handle 28b, and in the embodiment shown in the drawings, the handle is provided with an outlet 30 into which a plug 31 is inserted, whereby said plug is soldered, glued or otherwise permanently attached to the cable 13 end.

When the handle 28b is pressed forward (in the direction away-up) so that the spindle part 28a is introduced into the bore 29 completely, the cage 14 is adjusted to its advanced and extended position, as shown. in fig. 1 and 4. When you want to pull the cage back and fold it together, you proceed in such a way that the handle is simply pulled back to the one with dotted lines in fig. 1 shown position, whereby the far end of the instrument gets the in fig. 2 showed appearance.

One sees in fig. 1 that the stopper 31 is not closed at its end, and more specifically that the one with the designation 16 in fig. 3 cavity in the cable is available for injection or draining of fluid by the handle's prodding. A radiopaque dye can thus be injected into the cable and into the cage area by inserting the slanted tip of a suitable injection syringe into the opening 3 2 in the stopper 30 and pressing the syringe's fluid content into the cable's cavity. If one therefore considers introducing a dye into the ureter (or any other time) as part of the medical examination, apart from the intention being that the introduction will take place later in the ureter to remove stones or stones, the present instrument entails a reduction of work effort, time and risk under these conditions, since the instrument enables both goals to be achieved with a single introduction.

The benefits of providing a drainage path should be obvious. If desired, a suitable drain pipe can be connected to the handle end of the pressure piston (plugging) so that the fluid is led to a suitable vessel (not shown). It should be observed that one of the risks present when it comes to removing stones by means of manipulations with instruments of the general type in question is that a stone may strongly resist abduction after it is captured in the instrument cage. In that case, a urologist may prefer to wait sometimes as long as days, in the hope that the ureter may relax and allow the trapped stone to be removed by the instrument. However, it may happen that this method cannot be followed, namely if flow through the ureter is completely blocked by the stone 6g the instrument. This often raises the question of an abdominal operation (laparotomy), sometimes as an emergency measure. Self.' if the instrument according to the present invention does not eliminate the need for laparotomy if the captured stone cannot be extracted after a reasonable interval, the instrument in question means that it is no longer so critical to immediately take precautions, as the instrument can be left in position, whereby the cable continues to form a drainage path until a facilitating surgical intervention is performed.

Fig. 6 and 7 illustrate a modified construction where a fiber optic bundle 33 extends from the cage 14 through the cavity 16 in the cable and completely through the handle 11. This light-transmitting bundle can be slidably arranged in the cavity so that the far end of the bundle can be brought closer to a stone (or some other blocking object) in the vicinity of the cage 14. For this purpose, a handle 34, which is schematically shown in fig. 6, be attached by said bundle, whereby the handle. 34 can be brought into engagement with the cable 13's end (or with the handle 11) to limit the extent to which the fiber optic bundle's distal end can be introduced into the cage 14.

Except when it comes to the application described here, the fiber bundle 33 can be completely conventional. Certain of the light-transmitting fibers, such as the fibers 33a, are connected to a suitable light source 35. Other fibers in the bundle, such as the fibers 33b, are connected to an eyepiece 36. Although the fibers 33b are not oriented or image-transmitting, presence of a stone or other blocking object in the cage 14 perceptible by an experienced person, as a change (increase) in the intensity of reflected light occurs. In such cases, however, it is considered necessary or desirable to be able to see. the operative course, the fibers 33b can be oriented in such a way that images are transferred to the eyepiece.

As the fiber bundle 33 does not occupy the entire cavity 16, the advantages of visual control can be achieved without having to sacrifice the above-mentioned advantages, as the cavity is utilized for injecting and withdrawing fluid.

Figs. 8 and 9 further illustrate an embodiment which is identical to the embodiments described above and shown in the drawings, except that the fiber optic bundle 133 has an annular cross-section and limits a channel 137 in which a transmission line 138 for ultrasound energy is inserted. The handle 134, the light source 135 and the eyepiece 136 work in the same way as

the corresponding parts 34 - 36 in the embodiment according to fig. 6<*>and 7. The organ 138 for transmitting ultrasonic energy can be connected to a handle 139 in such a way that the tip 138a of the organ located at the far end can be fed until it comes into direct contact with a stone caught in the cage 14. The energy-conducting body's opposite end is connected to an ultrasound generator 140. Since production

and the transmission of ultrasound waves represents, a technique that is known and available to the person skilled in the art, should it be unnecessary with a detailed description of the associated organ and their working method, but instead it should only be noted that such elements can be combined with an expandable cage that can hold a captured stone (or other blocking object) in position, so that the tip of the ultrasound guide located at the far end can be brought into engagement with said stone. It is important that the stone is made immobile, and that there is direct contact between the stone and the conductor when it comes to achieving ice crushing of the stone using ultrasound.

Although fig. 8 and 9 show an instrument in which the cavity in the cable 13 has access to both a light-conducting member and an ultra-sound transmission member, it should be noted that one or the other of these members can be excluded. Thus, the acoustic transmission line or wire 138 can be located in the cavity 16 without needing to be surrounded by the fibers in the tubular bundle 133, and conversely the tubular bundle can be located in the cavity without the ultrasound transmission line 138 also having to be present. In the latter case, the channel 137 in the tubular bundle 133 can advantageously be used to promote injection and withdrawal of fluid.

It should be obvious from the above that the dimensions can vary to a considerable extent in the instruments which carry out embodiments of the present invention. For the sake of completeness, however, the following dimensions are indicated which have been found to be suitable for an instrument of the type in question: total length of the instrument 10 = 762: length of the extension tip 26 = 38 mm; the outer diameter of the twisted cable 13 and the cable tip 23 = 0.61 mm; the length of the cage 14 (ie the distance between the far end of the sleeve 12 and the ring 22 when the cage is extended) = approx. 29.2mm; the diameter of the cage 14 in the extended state = approx. 16.0mm; the diameter of each wire 15 = 0.2 mm; radial dimension of the annular strip 17 = approx. 0.05mm; 16 diameter of the cavity = approx. 0.20 mm (enlarged to approx. 1.27 mm if the light and/or supersonic conductor is placed therein, whereby the size of other components is regulated in a corresponding way).

Claims (20)

1. Instrument (10) for use in locating obstructing objects in body corridors and for removing said objects from the corridors, characterized in that it includes a flexible tube (12) with an end and an end and with a channel extending in the longitudinal direction through said pipe, in addition to a flexible cable (13) which extends through said channel, whereby said cable includes a collapsible cage (14) and is slidable in the channel between a first position in which the cage (14) is folded and retracted in said channel at the far end of the pipe (12), and a second position in which the cage (14) is extended and extended beyond the far end of the pipe (12), and a handle (11) which is connected to the cable at the near end of the pipe (12) selective displacement of the cage (14) between its retracted and extended positions, whereby a cavity (16) extends axially through the cable (13) and communicates with said cage (14) while providing a fluid path. 2. Instrument according to claim 1, characterized in that said cable (13). is longer than said pipe (12). 3. Instrument according to claim 1, characterized in that the cable (13) is formed entirely of wires (15) which extend from one end of the cable (13) to the other, whereby said wires (15) are tightly twisted together from the cage ( 14) to the handle (11). 4. Instrument according to claim 3, characterized in that said wires consist of spring wire. 5. Instrument according to claim 4, characterized in that said threads (15) are wound in tight contact with each other and thereby form a single layer that extends peripherally around said cavity (16). 6. Instrument according to claim 1, characterized * in that an elongate conductive member extends through said cavity (16) from the far end of the pipe (12) to a point past the near end of the pipe (12). 7. Instrument according to claim 6, characterized in that the conducting body includes a light-transmitting fiber optic tic bundle (33). 8. Instrument according to claim 7, characterized in that the fiber optic bundle (33) is axially slidable in said cavity (16). 9. Instrument according to claim 7, characterized in that certain fibers in the fiber optic bundle (33) are connected to a light source (35) and that other fibers are connected to an eyepiece (36), whereby the light source (35) and the eyepiece (36) is placed outside the instrument (10) past the end of the tube (12). 10. Instrument according to claim 9, characterized in that the fibers connected to the eyepiece (36) are oriented for image transmission. 11. Instrument according to claim 9, characterized in that said fiber bundle (133) is annular in cross-section and limits a channel (137) which extends axially through it. 12. Instrument according to claim 11, characterized in that a conductor (138) which can transmit ultrasound energy extends through said channel (137) in the fiber optic bundle (133). 13. Instrument according to claim 12, characterized in that the ultrasound transmission conductor (138) is slidably arranged in said channel (137) in the fiber optic bundle (133) and that the instrument is provided with a handle (139) for axial displacement of said conductor (138) so that its far end is pressed into the cage (14) when the cage is expanded so that said far end can engage with a blocking object enclosed in said cage (14). 14. Instrument according to claim 13, characterized in that said line is operatively connected to an ultrasound wave generator (140). 15. Instrument according to claim 6, characterized in that the conductive member includes an ultrasound wave transmission line. 16. Instrument according to claim 15, characterized in that said ultrasound wave transmission line is axially movable in said "cavity (16), that a handle (139) is arranged to axially displace the line in the cavity (16) in order to press the line's far end against the cage (14) when this is expanded, and for contact with a blocking object captured in the cage (14), and that an ultra-sound wave generator (140) is operatively connected to said line. 17. Instrument according to claim 1, characterized in that the cage (14) has a mainly pear-shaped contour when it is extended and extended, whereby the larger end of the pear-shaped cage constitutes the feeder. 18. Instrument according to claim 1, characterized in that the tube (12) is transparent. 19. Instrument according to claim 18, characterized in that the cable (13) at selected points along its length is provided with markings which are visible through the transparent wall of the pipe (12). . 20. Instrument according to claim 18, characterized in that the inner diameter of the tube (12) is significantly larger than the outer diameter of the cable (13), so that an annular space is formed between them.